Preparation of Ce/ferroferric oxide/food waste‐derived biochar for aqueous Cr(VI) adsorption

Abstract BACKGROUND Cr(VI) in aqueous solution is a serious concern that can harm human health by accumulating in the food chain. Meanwhile, the most common form of food waste (FW) disposal by landfill takes up a lot of area and pollutes the environment. As a consequence, FW was employed as a raw material in the production of food waste‐derived biochar (FWB), which was then modified to produce a Ce/Fe3O4/FWB composite for high‐efficiency Cr(VI) removal RESULTS The structure, morphology, and properties of the Ce/Fe3O4/FWB composite were thoroughly investigated, as well as its Cr(VI) adsorption ability. The composite exhibited the highest Cr(VI) adsorption of 20.4 mg/g at pH 2. Furthermore, the adsorption fitted the pseudo‐second‐order kinetic model and the Langmuir model, with intra‐particle diffusion acting as the rate‐controlling step. The thermodynamic investigation demonstrated that Cr (VI) adsorption by Ce/Fe3O4/FWB was a spontaneous endothermic process. With increasing concentrations of Cl − , SO 4 2− and PO 4 3− , the Cr(VI) adsorption was weakened in the sequence of Cl − , SO 4 2− and PO 4 3− . CONCLUSION Adsorbent preparation utilizing FW as raw material is a sustainable and environmentally beneficial method for FW reclaimation and Cr(VI)‐bearing wastewater treatment. © 2022 Society of Chemical Industry (SCI).